Inhibition of dynamin prevents CCL2-mediated endocytosis of CCR2 and activation of ERK1/2
Inhibition of dynamin prevents CCL2-mediated endocytosis of CCR2 and activation of ERK1/2
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DOI：
10.1016/j.cellsig.2009.07.010
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发表时间：
2009-12-01
影响因子：
4.8
通讯作者：
Fischer, T.
中科院分区：
文献类型：
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作者：
Garcia Lopez, M. A.;Aguado Martinez, A.;Fischer, T.
C 蛋白偶联受体 (GPCR) 信号的强度和持续时间通过脱敏机制进行调节。在白细胞中，配体与趋化因子受体结合导致 Ca2+ 动员和通过百日咳毒素敏感 G 蛋白激活 ERK，以及 GPCR 磷酸化。与内吞机制（网格蛋白、适应素）相互作用后，接头 P-arrestin 识别磷酸化的 GPCR 尾部并猝灭向受体发出的信号。然而，导致受体内吞作用的分子机制在 GPCR 中并不普遍，并且 CCR2 趋化因子受体内化的精确空间和时间事件仍然未知。在这里，我们表明，配体结合后，CCR2 迅速内化并到达早期内体，然后到达溶酶体。 RNA 干扰导致的网格蛋白敲低会损害 CCR2 内化，动力抑制剂 dynasore 的治疗也是如此。我们的结果表明，CCR2 内化使用网格蛋白依赖性和独立性途径的组合，正如在其他趋化因子受体中观察到的那样。此外，dynasore 的使用使我们能够确认调节 ERK1/2 激活的动力敏感元件的存在。我们的结果表明受体内化和细胞信号传导之间的联系更加复杂。 (C) 2009 Elsevier Inc. 保留所有权利。
The magnitude and duration of C protein-coupled receptor (GPCR) signals are regulated through desensitization mechanisms. In leukocytes, ligand binding to chemokine receptors leads to Ca2+ mobilization and ERK activation through pertussis toxin-sensitive G proteins, as well as to phosphorylation of the GPCR. After interaction with the endocytic machinery (clathrin, adaptin), the adaptor P-arrestin recognizes the phosphorylated GPCR tail and quenches signaling to receptors. The molecular mechanisms that lead to receptor endocytosis are not universal amongst the GPCR, however, and the precise spatial and temporal events in the internalization of the CCR2 chemokine receptor remain unknown. Here we show that after ligand binding, CCR2 internalizes rapidly and reaches early endosomes, and later, lysosomes. Knockdown of clathrin by RNA interference impairs CCR2 internalization, as does treatment with the dynamin inhibitor, dynasore. Our results show that CCR2 internalization uses a combination of clathrin-dependent and -independent pathways, as observed for other chemokine receptors. Moreover, the use of dynasore allowed us to confirm the existence of a dynamin-sensitive element that regulates ERK1/2 activation. Our results indicate additional complexity in the link between receptor internalization and cell signaling. (C) 2009 Elsevier Inc. All rights reserved.